Study Data


MS Study

Project uploaded by: Yashwant
Project ID: IMP_100044
Title: (p)ppGpp and DksA play crucial role in reducing the efficacy of ꞵ-lactam antibiotics by modulating bacterial membrane permeability
Project Description: The key signaling molecules in the bacterial stress sensing pathway, the alarmone (p)ppGpp and transcription factor DksA, help in survival during nutritional deprivation and exposure to xenobiotics by modulating cellular metabolic pathways. In Vibrio cholerae, (p)ppGpp metabolism is solely linked with the functions of three proteins: RelA, SpoT, and RelV. At threshold or elevated concentrations of (p)ppGpp, the level of cellular metabolites and proteins in the presence and absence of DksA in V. cholerae and other bacteria has not yet been comprehensively studied. We engineered the genome of V. cholerae to develop DksA null mutants in the presence and absence of (p)ppGpp biosynthetic enzymes. We observed a higher sensitivity of the (p)ppGpp0ΔdksA V. cholerae mutant to different ꞵ-lactam antibiotics compared to the wild-type (WT) strain. Our whole-cell metabolomic and proteome analysis revealed that the cell membrane and peptidoglycan biosynthesis pathways are significantly altered in the (p)ppGpp0, ΔdksA, and (p)ppGpp0ΔdksA V. cholerae strains. Further, the mutant strains displayed enhanced inner and outer membrane permeability in comparison to the WT strains. These results directly correlate with the tolerance and survival of V. cholerae to ꞵ-lactam antibiotics. These findings may help in the development of adjuvants for ꞵ-lactam antibiotics by inhibiting the functions of stringent response modulators.
Research Area: Biological Sciences
Funding Source: Translational Research Program (TRP) (No. BT/PR30159/MED/15/188/2018) of Department of Biotechnology (DBT), Govt. of India.
Project Contributors: Yashwant Kumar

Study uploaded by: Yashwant
Study ID: IMS_100038
Title: (p)ppGpp and DksA play crucial role in reducing the efficacy of ꞵ-lactam antibiotics by modulating bacterial membrane permeability
Summary: The key signaling molecules in the bacterial stress sensing pathway, the alarmone (p)ppGpp and transcription factor DksA, help in survival during nutritional deprivation and exposure to xenobiotics by modulating cellular metabolic pathways. In Vibrio cholerae, (p)ppGpp metabolism is solely linked with the functions of three proteins: RelA, SpoT, and RelV. At threshold or elevated concentrations of (p)ppGpp, the level of cellular metabolites and proteins in the presence and absence of DksA in V. cholerae and other bacteria has not yet been comprehensively studied. We engineered the genome of V. cholerae to develop DksA null mutants in the presence and absence of (p)ppGpp biosynthetic enzymes. We observed a higher sensitivity of the (p)ppGpp0ΔdksA V. cholerae mutant to different ꞵ-lactam antibiotics compared to the wild-type (WT) strain. Our whole-cell metabolomic and proteome analysis revealed that the cell membrane and peptidoglycan biosynthesis pathways are significantly altered in the (p)ppGpp0, ΔdksA, and (p)ppGpp0ΔdksA V. cholerae strains. Further, the mutant strains displayed enhanced inner and outer membrane permeability in comparison to the WT strains. These results directly correlate with the tolerance and survival of V. cholerae to ꞵ-lactam antibiotics. These findings may help in the development of adjuvants for ꞵ-lactam antibiotics by inhibiting the functions of stringent response modulators.
Publication:
Release Date: Aug. 13, 2025
Study Type: Mass Spectrometry (MS)
Data Type: Untargeted
IEC/IBSC Approval Number :

Sr.No Sample ID Sample Name Organism Source Sample Preparation Protocol Sample Type Experimental Condition Time of treatment Variant/Variety Gender Age Replicates Storage Conditions Extraction Protocol Number of files per sample
71 IMSM_102121 N16_5 Vibrio cholerae | 666 Bacteria The cells were pelleted down again by centrifugation (10,000 rpm at 4°C for 10 min), washed with 0.9% normal saline and stored at -80°C. To extract the intracellular metabolites cold 100% methanol was added (Sigma Aldrich; Cat no. 34860) followed by vortexing and bath sonication for 10 min (Bransonic® Ultrasonic M Cleaning Bath 1510). The cell debris was pelleted down by centrifugation (10,000 rpm at 4°C for 10 min) and supernatant was collected in two separate microcentrifuge tubes (120 µL each tube), vacuum dried (Thermo Scientific™ Savant™ SPD1010) and stored at -80°C. For the analysis of metabolites, the dried supernatant was dissolved in 60 µL of 15% methanol or 50% acetonitrile (Cat no. 271004) followed by vortexing for 5 min and centrifuged (10,000 rpm for 10 min). The supernatant was collected in a separate sample vial (Supelco™ Analytical). wild type Untreated overnight at 37°C NA NA NA NA –80ºC

The cells were pelleted down again by centrifugation (10,000 rpm at 4°C for 10 min), washed with 0.9% normal saline and stored at -80°C. To extract the intracellular metabolites cold 100% methanol was added (Sigma Aldrich; Cat no. 34860) followed by vortexing and bath sonication for 10 min (Bransonic® Ultrasonic M Cleaning Bath 1510). The cell debris was pelleted down by centrifugation (10,000 rpm at 4°C for 10 min) and supernatant was collected in two separate microcentrifuge tubes (120 µL each tube), vacuum dried (Thermo Scientific™ Savant™ SPD1010) and stored at -80°C. For the analysis of metabolites, the dried supernatant was dissolved in 60 µL of 15% methanol or 50% acetonitrile (Cat no. 271004) followed by vortexing for 5 min and centrifuged (10,000 rpm for 10 min). The supernatant was collected in a separate sample vial (Supelco™ Analytical).

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72 IMSM_102122 N16_6 Vibrio cholerae | 666 Bacteria The cells were pelleted down again by centrifugation (10,000 rpm at 4°C for 10 min), washed with 0.9% normal saline and stored at -80°C. To extract the intracellular metabolites cold 100% methanol was added (Sigma Aldrich; Cat no. 34860) followed by vortexing and bath sonication for 10 min (Bransonic® Ultrasonic M Cleaning Bath 1510). The cell debris was pelleted down by centrifugation (10,000 rpm at 4°C for 10 min) and supernatant was collected in two separate microcentrifuge tubes (120 µL each tube), vacuum dried (Thermo Scientific™ Savant™ SPD1010) and stored at -80°C. For the analysis of metabolites, the dried supernatant was dissolved in 60 µL of 15% methanol or 50% acetonitrile (Cat no. 271004) followed by vortexing for 5 min and centrifuged (10,000 rpm for 10 min). The supernatant was collected in a separate sample vial (Supelco™ Analytical). wild type Untreated overnight at 37°C NA NA NA NA –80ºC

The cells were pelleted down again by centrifugation (10,000 rpm at 4°C for 10 min), washed with 0.9% normal saline and stored at -80°C. To extract the intracellular metabolites cold 100% methanol was added (Sigma Aldrich; Cat no. 34860) followed by vortexing and bath sonication for 10 min (Bransonic® Ultrasonic M Cleaning Bath 1510). The cell debris was pelleted down by centrifugation (10,000 rpm at 4°C for 10 min) and supernatant was collected in two separate microcentrifuge tubes (120 µL each tube), vacuum dried (Thermo Scientific™ Savant™ SPD1010) and stored at -80°C. For the analysis of metabolites, the dried supernatant was dissolved in 60 µL of 15% methanol or 50% acetonitrile (Cat no. 271004) followed by vortexing for 5 min and centrifuged (10,000 rpm for 10 min). The supernatant was collected in a separate sample vial (Supelco™ Analytical).

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Sr.No MS Exp ID Sample Name/ID Mass Spectrometer Type MS Instrument Name MS Instrument type MS Ionization Method Ion Mode/Scan Polarity Data Transformation (Software/s Used)
1 IME_101273 JV7_1 / IMSM_102057 LCMS (Liquid Chromatography- Mass Spectrometry) Thermo Fusion Orbitrap Orbitrap Electrospray Ionization - ESI Negative NA
2 IME_101274 JV7_2 / IMSM_102058 LCMS (Liquid Chromatography- Mass Spectrometry) Thermo Fusion Orbitrap Orbitrap Electrospray Ionization - ESI Negative NA
3 IME_101275 JV7_3 / IMSM_102059 LCMS (Liquid Chromatography- Mass Spectrometry) Thermo Fusion Orbitrap Orbitrap Electrospray Ionization - ESI Negative NA
4 IME_101276 JV7_4 / IMSM_102060 LCMS (Liquid Chromatography- Mass Spectrometry) Thermo Fusion Orbitrap Orbitrap Electrospray Ionization - ESI Negative NA
5 IME_101277 JV7_5 / IMSM_102061 LCMS (Liquid Chromatography- Mass Spectrometry) Thermo Fusion Orbitrap Orbitrap Electrospray Ionization - ESI Negative NA
6 IME_101278 JV7_6 / IMSM_102062 LCMS (Liquid Chromatography- Mass Spectrometry) Thermo Fusion Orbitrap Orbitrap Electrospray Ionization - ESI Negative NA
7 IME_101279 JV8_1 / IMSM_102063 LCMS (Liquid Chromatography- Mass Spectrometry) Thermo Fusion Orbitrap Orbitrap Electrospray Ionization - ESI Negative NA
8 IME_101280 JV8_2 / IMSM_102064 LCMS (Liquid Chromatography- Mass Spectrometry) Thermo Fusion Orbitrap Orbitrap Electrospray Ionization - ESI Negative NA
9 IME_101281 JV8_3 / IMSM_102065 LCMS (Liquid Chromatography- Mass Spectrometry) Thermo Fusion Orbitrap Orbitrap Electrospray Ionization - ESI Negative NA
10 IME_101282 JV8_4 / IMSM_102066 LCMS (Liquid Chromatography- Mass Spectrometry) Thermo Fusion Orbitrap Orbitrap Electrospray Ionization - ESI Negative NA

Sr.No First name Last name Email Organization Designation
1 Yashwant Kumar y.kumar@thsti.res.in Translational Health Science And Technology Institute (THSTI) scientist

Sr.No ftprun ID MS Exp ID MS Data Files
21 IMR_101897 IME_101293 HILIC_NEG_MC3_3.mzXML
22 IMR_101898 IME_101294 HILIC_NEG_MC3_4.mzXML
23 IMR_101899 IME_101295 HILIC_NEG_MC3_5.mzXML
24 IMR_101900 IME_101296 HILIC_NEG_MC3_6.mzXML
25 IMR_101901 IME_101297 HILIC_NEG_MC4_1.mzXML
26 IMR_101902 IME_101298 HILIC_NEG_MC4_2.mzXML
27 IMR_101903 IME_101299 HILIC_NEG_MC4_3.mzXML
28 IMR_101904 IME_101300 HILIC_NEG_MC4_4.mzXML
29 IMR_101905 IME_101301 HILIC_NEG_MC4_5.mzXML
30 IMR_101906 IME_101302 HILIC_NEG_MC4_6.mzXML